Hi might sound like a daft question but i was thinking of getting bg244 for my 1.6tdci just to keep thing running as they should. But how do you get any of it in the fuel tank? I used to use redex diesel regularly on my old car but I couldn't get that in the filler cap when I bought the car :-/

Dunno on my corsa it had spring loaded flap like the focus and to be fair I just added a bit into the filler hole slowly and it seeped through. On the focus if its same as my petrol I'm sure you could just use a thin screw driver or something to open the flap then slowly freed it in. Millers has a filling nozzle too which may help too

I got a plastic filler funnel with my Focus, which also has a smart filler cap. It pushes in so you can use additive or if you were to run out of fuel, so you could use a can. It's exactly the same size as the filler nozzle on a diesel pump so it opens the flap